Archive through November 27, 2007

[mgonitzke]

C'mon, now, I even got that...

 

[ljerickson]

Alexander,

You might consider re-boring to the K321 3.5" bore. This is only 1/8" overbore. If you go to a sleeve, it's probably good to go 1/8" per side which means a 3.625" bore.

I'm not totally up to speed, but it might be a good idea update to the larger K321 exhaust valve too.

The absolute safe way to go, is to get a used block and bore and hone to a standard oversize.

Some of the guys here may have done the K301 to K321 upgrade and I hope they speak up.

I guess I have a hard time blaming the previous owner too much, if it starts too smoke gray, an overbore is the only way to go. On a 40 year old tractor 1, 2, or 3 overhauls might not be out of the question. I'm finding out that on my 122, if it can wear out it probably is.

Lee

 

[adjordjevich]

I noticed that my engine has no balance gears, but one on ebay with the same 4759B spec appears to. Any ideas?

Also, once this engine is rebuilt would synthetic oil keep her going longer.

 

[mgonitzke]

Alexander D.-

Earlier tractors had engines without balance gears, i.e., your 122 while newer tractors, such as my 128 and 1650 have (had) balance gears. That block is probably from a slightly newer cub. You can use it without the balance gears, everything else is the same. I use semi-synthetic in everything I have and have no problems. A lot of people run Mobil 1 and seem to like it. It was in my 1450 when I got it and I'm fairly impressed with it. Just use dino oil when you break it in so the rings seat.

 

[dtanner]

Chris Pearson (Cpearson) our sponsers above have those washers for sale

 

[wmiller]

Alexander
IH used to supply short blocks and complete replacement engines. My dad replaced the complete engine in my 126 yrs ago and it has/had balance gears,however the engine has a different spec # than the original,however if someone replaced just the short block, the ID tag would not have been changed since it is on the blower housing which would have been reused. A complete replacement engine was painted black and had an ID sticker instead of a metal tag.

 

[dfrisk]

I've never had a block worn bad enough to consider sleeving one but I suppose it can be done. Problem with going too much oversize on bore is there isn't a lot of material left once You enlarge the bore and the head and top portion of the cylinder has been known to crack and break off ruining the block. Those fins used to cool the barrel are REALLY good stress risers and propagate cracks really well. Somebody who knows the spec numbers better than I do should be around that will explain which blocks can be bored the 1/8" O/S to convert a K301 (12 hp) to K321 (14 hp)

 

[theaton]

I have a K301A that has a .010 overbore,what would that make the horsepower? Everthing else in the engine is stock

 

[mgonitzke]

Todd H.-

12 h.p. That .010" oversize is really negligible. You don't really gain much displacement. I can't remember the stroke of a K301, but at 10 over and if I was to assume that the stroke was 3 inches, then the increase in displacement is a mere .044 cubic inches. I'm thinking the stroke is less than 3, so it could be even less of an increase than that.

 

[dfrisk]

TODD - Matt's right, a K301 is 3-3/8" bore & 3-1/4" stroke so a .010" over-bore only increases displacement from 29.075 cid to 29.2476 cid...or .1726 cid more...so if You were 12.000 HP you would now be 12.0712364573 HP at .010" over........ MAN I love to play with calculators!

 

[theaton]

Alexander D, my K301A has no balance gears from the serial # off the engine plate mine is a 1967 block with a spec no. of 4763B. I inquired a while back to the serial number brake for engine with or without balance gears. The response I got was that there was either no info or nobody knew. I am anxious if anybody out there has this knowledge

 

[theaton]

Thanks Dennis, that extra .07 of power does really make a difference for those big loads! HA HA HA

 

[aschumacher]

While tucking in my Cub today for the winter, I remembered one last thing to do. If you have a high-pressure washer and store it outside, dont forget to put anti-freeze in the pump part. Pressurized cans are available, or maybe RV A/F if you can get it into the pump.

 

[dmerkle]

I have 2 K321 motors that have a sleeve in them. One has a stock rebuild done to it and it runs great. Broken rod took out a lower part of the bore. Motor is in a 149 that goes to several plow days each year.

Second K321 was build following David Kirk's Hot Rod Kohler. It still has a few bugs to work out. I think it has a carb issue(s) in the upper RPM range. I haven't had time lately to work on it.

 

[kweaver]

Don V told me several years ago that a K301 had to be bored off center to stay out of the head bolt holes.

Alexander - Man you need to find a better class of women to hang out with

 

[jgperry]

Thanks, Digger, for the color info. Appreciate it.

 

[adjordjevich]

Super info guys. Since my k301 is already bored max and out of round, I've found a few bare blocks. Will all of my parts bolt up to any K301 and will it use the through pin for cam? Starter brackets, dipstick tube, oil pan, etc. All of this interchanges? Last, but not least..........my crank and bearing plate bolt directly in?

thanks,
alex

found one block with standard piston and one with .003 piston. These are my candidates.

 

[vthomley]

Allen Schumacher, thanks for the reminder note for winterizing my Pressure Washer. I have to take care of that tonight! I have to bottle of anti-freeze, just have to get the job done.
Thanks again,
Vince

 

[mgonitzke]

Alexander D.-

As long as they're CC-style blocks and not ones using an oil base instead of oil pan, then, yes.

 

[adjordjevich]

Does anyone out here have a model 122 with a K301, spec. 4759B. If so, I'd love a picture. I think someone may have played swap-a-roo with this cub. I want to compare someone's verified original engine with what I have. Better sooner than later.